The purpose of Medigap
Medigap is designed to supplement Original Medicare — not replace it. You must already have Part A and Part B to buy a Medigap policy. It then helps pay for the remaining out-of-pocket costs: deductibles, coinsurance, copays, and (in some cases) limited foreign travel emergency care.
Key principles to understand
- Requirement: You must have Medicare Part A and Part B to buy a policy.
- Structure: Policies cover one individual; spouses must buy separate policies.
- Provider choice: You can see any doctor or specialist nationwide who accepts Medicare — no network.
- No referrals: Visit specialists without going through a primary care gatekeeper.
- Guaranteed renewability: Policies cannot be canceled due to health conditions if premiums are paid on time.
Standardized plan types
Medigap plans are standardized by the federal government and labeled by letters (A, B, C, D, F, G, K, L, M, N). Each lettered plan offers the exact same coverage no matter which insurance company sells it.
- Plan F & Plan C: Comprehensive coverage, but only available to those eligible for Medicare before January 1, 2020.
- Plan G: The most popular plan for new enrollees — covers everything Plan F covers except the Part B deductible.
- Plan N: Lower premiums in exchange for small copays for some doctor and emergency room visits.
Open Enrollment Period
The best time to buy is during your 6-month Medigap Open Enrollment Period. This begins the month you turn 65 and are enrolled in Part B. During this window, insurance companies cannot use medical underwriting — meaning they cannot deny coverage or charge more for pre-existing conditions.
What Medigap covers
- Part A hospital coinsurance and hospital costs.
- Part B coinsurance or copayments.
- Blood transfusion costs (first 3 pints).
- Part A hospice care coinsurance.
- Skilled nursing facility care coinsurance.
- Foreign travel emergency care (up to plan limits, on certain plans).
What Medigap doesn't cover
- Prescription drugs (you'll need a separate Part D plan).
- Long-term care (like nursing home stays).
- Routine dental, vision, or hearing care.
- Eyeglasses and hearing aids.
- Private-duty nursing.
Medigap vs Medicare Advantage
- See any provider that accepts Medicare nationwide.
- Predictable out-of-pocket costs.
- Higher monthly premiums.
- Separate Part D drug plan required.
- Use the plan's network of providers.
- Lower (often $0) monthly premiums.
- Drug coverage usually included.
- Annual out-of-pocket maximum.